Hi David,
On 6/24/2019 6:55 AM, David Laight wrote:
From: Reinette Chatre
Sent: 19 June 2019 21:27
While the DOC at the beginning of lib/bitmap.c explicitly states that "The number of valid bits in a given bitmap does _not_ need to be an exact multiple of BITS_PER_LONG.", some of the bitmap operations do indeed access BITS_PER_LONG portions of the provided bitmap no matter the size of the provided bitmap. For example, if find_first_bit() is provided with an 8 bit bitmap the operation will access BITS_PER_LONG bits from the provided bitmap. While the operation ensures that these extra bits do not affect the result, the memory is still accessed.
I suspect that comment also needs correcting. On BE systems you really do need to have a array of longs.
Thank you very much for taking a look. I believe that the lib/bitmap.c documentation is correct, it is me that misinterpreted it and to make matters worse I only provided the portion I misinterpreted in my commit message. Before the portion that I quote above it is stated clearly that it is implemented using an array of unsigned longs.
Reinette